Localized unpaired electrons posses a magnetic moment in virtue of their angular and spin momentum. Such magnetic moment is sensitive to external magnetic fields, which can be used to probe and manipulate it both statically and dynamically. Molecules supporting unpaired electrons are routinely realized with organic radicals, coordination compounds of the first row of transition metals (TMs), and rare-earth ions. On the one hand, the study of molecular unpaired electrons' dynamics opens a windows on electronic structure and magnetism. Indeed, EPR studies of transition metals compounds have long provided a fundamental mean to address the relation between electronic structure, coordination geometry and magnetism[1]}. On the other hand, the interaction of spin with magnetic fields provides a rich opportunity to control and drive magnetic moment for specific tasks. Magnetic molecules have been proposed for a wide range of applications. For instance, they are routinely used for sensing, such as the use of spin probes to measure distances and dynamics in biological systems[2]}, or as contrast agents in Magnetic Resonance Imaging (MRI)[3]}. Magnetism is also another natural area of application for this class of systems. The design of magnetic molecules able to retain the direction of their magnetic moment for long times[4]}, commonly known as single-molecule magnets, has been one of the central goals for a large community of chemists, physicists and material scientists for a long time[5]}. More recently, the advent of disciplines such as spintronics[6]}, [7]}, [8]} and quantum science[9]}, [10]}, [11]}, [12]}, [13]} have also attracted the attention of the molecular magnetism community. For instance, it has been experimentally demonstrated that molecules can be embedded in solid-state spintronics[14]} devices to influence the flow of currents[15]}. Moreover, single molecules with long coherence times and addressable with single-qubit gates have already found application as building blocks of quantum architectures[16]}, [17]}, [18]}, [19]}. The implementation of two-qubit gates[20]} and quantum algorithms using molecular spins have already been demonstrated[21]}, and the areas of quantum initialization and read-out[22]}, scaling of the number of qubits[23]}, [24]}, [25]}, and the interface of molecules with other quantum systems[26]}, [27]}, [28]} are also rapidly progressing.
